Bone Graft Delivery Loading Assembly

ABSTRACT

A bone graft loading system includes a loading funnel, syringe, cannula, plunger, and loading tool. The loading funnel includes an interior passageway to receive the cannula and a syringe docking portion. The syringe may be coupled to the syringe docking portion so that it extends along a longitudinal axis that is transverse to the longitudinal axes of the cannula and the loading funnel. A user may advance bone graft from the syringe to a holding area of the loading funnel. The user may then move the loading tool through the holding area and into the interior space of the cannula to load the cannula with bone graft. This process may be repeated until the cannula is fully loaded with bone graft. The cannula and the plunger inside the cannula may then be removed from the loading funnel and coupled to an injector assembly for use in surgery.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/241,339, filed on Aug. 19, 2016, the disclosure of which is herebyincorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure relates to systems for delivering materials tobone during a surgical procedure, and more particularly methods andsystems for loading the materials into the delivery systems.

BACKGROUND

There is an increasing prevalence in minimally invasive spinalprocedures. For instance, percutaneous delivery of bone graft or bonegraft substitute to aid implants or screws (also potentially deliveredpercutaneously) in fixing and/or fusing portions of the spinal column.However, there are challenges to delivering such bone graft materialspercutaneously during minimally invasive surgical procedures. As usedherein, the term “bone graft” includes, but is not limited to bonegraft, bone graft alternative, bone graft substitute, bone marrowaspirate, demineralized bone matrix, or mixtures thereof, whetheroccurring naturally or artificially, unless specified otherwise. Itshould further be understood that the term bone graft may refer to,separately or in combination with any or all of the materials providedabove, bone marrow aspirate, blood, and saline.

Currently, in certain surgical procedures, bone graft is provided to asurgeon in a pre-loaded syringe. The surgeon may transfer the bone graftfrom the syringe to an injector device with the syringe and the injectordevice being aligned along the same axis. However, using pre-loaded bonegraft may reduce the ability of the surgeon to use a particular desiredbone graft for a particular procedure. Further, loading bone graft froma syringe to an injector device with both components aligned along thesame axis may be difficult because bone graft materials may behave asnon-Newtonian fluids. For example, some bone graft materials do not floweasily, particularly through funnel-like or conical geometries, from arelatively large holding area, such as a cylinder or tube, to arelatively small holding area.

Therefore, there exists a need for an improved bone graft deliveryloading assembly and methodology that addresses these and otherdrawbacks with prior art systems.

BRIEF SUMMARY

According to one embodiment of the disclosure, a bone graft loadingsystem includes a loading member having a passageway extending along afirst longitudinal axis, a container adapted to contain the bone graft,the container extending along a second longitudinal axis, and a cannulamember having an inner hollow space extending along a third longitudinalaxis. When the cannula member is received within the passageway of theloading member and the container is coupled to the loading member, thefirst and third longitudinal axes are parallel to one another andtransverse to the third longitudinal axis. The container may be asyringe member adapted to couple to a syringe docking portion of theloading member. A locking member may be positioned on a first end of theloading member, the locking member having two extension members andbeing rotatable about the first longitudinal axis. A proximal end of thecannula member may include a flange. When the cannula member is receivedwithin the passageway of the loading member, the locking member may becapable of rotation between a locked state in which the extensionmembers of the locking member inhibit proximal movement of the flange ofthe cannula member with respect to the loading member and an unlockedstate in which the flange of the cannula member is capable of proximalmovement with respect to the loading member.

A flange may extend radially outward from the loading member, and aspring may be positioned between the flange of the loading member andthe locking member, the spring biasing the locking member toward thefirst end of the loading member. The syringe docking portion may includea cylindrical member extending orthogonally from the longitudinal axisof the loading member, the syringe docking portion including a firstmating feature and the syringe member including a second mating featureadapted to couple to the first mating feature. The first mating featuremay include threads on an interior surface of the cylindrical member ofthe syringe docking portion, and the second mating feature may includethreads on an exterior surface of a distal end of the syringe member.

A plunger member may be adapted to be received within the inner hollowspace of the cannula member. The plunger member may include a pluralityof teeth along a length of the plunger member. An elastomeric seal maybe adapted to couple to a distal tip of the plunger member. When theplunger member is received within the inner hollow space of the cannulamember, the elastomeric seal may form a fluid tight seal between theelastomeric seal and the inner hollow space of the cannula member.

The syringe docking portion may include a first face with an openingtherein, and an aperture in fluid communication with the passageway ofthe loading member. When the cannula member is received within thepassageway of the loading member, an open distal tip of the cannulamember may be positioned adjacent the aperture of the syringe dockingportion. The aperture of the syringe docking portion may have a diameterthat is smaller than a diameter of the open distal tip of the cannulamember. The first face may have a concave profile. When the syringemember is coupled to the syringe docking portion, a distal end of thesyringe member may be positioned between the opening in the first faceof the syringe docking portion and the aperture of the syringe dockingportion. A loading tool may have a handle and a cylindrical shaftextending distally from the handle. The cylindrical shaft may have anexternal diameter that is smaller than a diameter of the aperture of thesyringe docking portion and also smaller than a diameter of the innerhollow space of the cannula. The loading tool may include a distal tipportion extending distally from the cylindrical shaft, the distal tipportion having the shape of a half cylinder. A terminal end of thedistal tip portion of the loading tool may include a recess having ashape of a portion of a sphere.

According to another aspect of the disclosure, a method of loading bonegraft into a bone graft delivery system includes (i) coupling a syringemember containing bone graft to a loading member so that a longitudinalaxis of the syringe member is transverse to a longitudinal axis of theloading member; (ii) positioning a cannula member within a passageway ofthe loading member so that a longitudinal axis of the cannula member isparallel to the longitudinal axis of the loading member; (iii) advancingbone graft from the syringe to the loading member; and (iv) inserting aloading tool into an interior space of the cannula to advance bone graftfrom the holding area to the interior space of the cannula. The methodmay include repeating steps (iii) and (iv). A plunger member may beinserted into the interior space of the cannula member prior topositioning the cannula member within the passageway of the loadingmember. An elastomeric seal may be positioned onto a distal tip of theplunger member prior to inserting the plunger member into the interiorspace of the cannula. Prior to positioning the elastomeric seal onto thedistal tip of the plunger, the elastomeric seal may be positioned withina sterile package. The sterile package may include a base portionconnected to a lid portion by a hinge, and the hinge may bias the lidportion away from the base portion into an open condition in the absenceof applied force. The step of inserting the plunger member into theinterior space of the cannula member may include forming a fluid tightseal between the elastomeric seal and the interior space of the cannulamember.

The method may further include removing the cannula member from theloading member while the plunger member is still within the cannulamember, and then coupling the cannula member and the plunger member to ahandle assembly adapted to advance the plunger member relative to thecannula member. The step of positioning the cannula member within thepassageway of the loading member may include advancing the cannulamember until a proximal flange of the cannula member contacts theloading member. A locking hub of the loading member may be rotated sothat extension members of the locking hub overlie the proximal flange ofthe cannula member. The bone graft may be manually loaded into thesyringe member prior to coupling the syringe member to the loadingmember. The step of coupling the syringe member to the loading membermay be performed so that the longitudinal axis of the syringe member isorthogonal to the longitudinal axis of the loading member. The bonegraft advanced from the syringe to the loading member may be firstadvanced to a holding area of the loading member that is spaced apartfrom the cannula member. The step of inserting the loading tool into theinterior space of the cannula may include inserting the loading toolthrough the holding area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bone graft injector assembly accordingto an embodiment of the disclosure.

FIGS. 2A-C are various views of a handle subassembly of the injectorassembly of FIG. 1.

FIGS. 3A-C are various views of a plunger subassembly of the injectorassembly of FIG. 1.

FIGS. 3D-F are various views of a seal member of the plunger subassemblyof FIGS. 3A-C.

FIG. 3G is a perspective view of packaging to store the seal member ofFIGS. 3D-F or other components.

FIGS. 4A-D are various views of a delivery tube subassembly of theinjector assembly of FIG. 1.

FIGS. 5A-F are various views of a loading funnel according to anembodiment of the disclosure.

FIGS. 6A-B are various views of a syringe assembly according to anembodiment of the disclosure.

FIGS. 7A-C are various views of a loading tool according to anembodiment of the disclosure.

FIG. 8 is a flowchart of a method of loading bone graft into a deliverytool according to an embodiment of the disclosure.

FIGS. 9A-G are various views of steps of the flowchart of FIG. 8.

FIG. 10 is a partially transparent view of a syringe docking end of theloading funnel of FIGS. 5A-F.

DETAILED DESCRIPTION

As used herein, the term “proximal” refers to a location closer to asurgeon or other personnel using the device as described herein, whilethe term “distal” refers to a location farther away from the surgeonusing the device.

An injector assembly 100 of a bone graft delivery system is illustratedin FIG. 1 according to an embodiment of the disclosure. Injectorassembly includes a number of subassemblies including, for example, ahandle subassembly 200, a ratchet subassembly 300, a plunger subassembly400, and a delivery tube subassembly 500. Handle subassembly 200 may beused to advance plunger subassembly 400 in an incremental or continuousfashion through delivery tube subassembly 500 to force a material out ofa distal end thereof. For embodiments with incremental advancement ofplunger subassembly 400, handle subassembly 200 and the plungersubassembly may work in conjunction with ratchet subassembly 300 tofacilitate the incremental advancement.

Handle subassembly 200, illustrated in FIGS. 2A-C, includes a fixed arm210 coupled to a moving arm 220 by a fastener, for example a pivot pin230. A first retaining feature 240 may extend from a superior proximalportion of fixed arm 210. First retaining feature 240 may be generally“U” or “C” shaped, forming a laterally facing recess sized and shaped toreceive a portion of plunger subassembly 400. A second retaining feature250 extends from a superior distal portion of fixed arm 210. Secondretaining feature 250 may also be generally “U” or “C” shaped, forming alaterally facing recess sized and shaped to receive a portion ofdelivery tube subassembly 500. For instance, second retaining feature250 may include a slot 252 to receive a flange 520 of cannula 510securely therein, which is described in greater detail below.

Moving arm 220 includes an upwardly extending member 222 configured toextend through a slot in fixed arm 210. Upwardly extending member 222may include a first aperture to receive pivot pin 230 so that moving arm220 may pivot with respect to fixed arm 210. Upwardly extending member222 may include a second aperture at a superior end to receive anotherfastener such as pin 232 for coupling to a portion of ratchetsubassembly 300.

Ratchet subassembly 300 includes a spring 310 and a pawl 320. Spring 310may be positioned within the slot of fixed arm 210, with a first end ofthe spring 310 abutting a distal end of the slot and a second end of thespring 310 abutting a portion of upwardly extending member 222 of movingarm 220. With this configuration, fixed handle 210 is biased away frommoving handle 220 about pivot pin 230 by spring 310. In other words, auser may squeeze moving arm 220 toward fixed arm 210, which advancespawl 320 distally while compressing spring 310. As the user relaxes thegrip, moving arm 220 will move distally with respect to fixed arm 210 asspring 310 decompresses and pawl 320 moves proximally. Pawl 310 may havea substantially flat distal face so that, as a user squeezes fixed arm210 and moving arm 220 causing pawl 310 to advance forward, the flatdistal face and/or a corner thereof engages a surface of a component ofplunger subassembly 400, which is described in greater detail below,causing plunger subassembly 400 to advance forward with each iterativesqueeze. Upon releasing compression of the moving arm 220, the pawl 310may pivot slightly about pin 232, allowing for pawl 310 to easily moveproximally without engaging any other surfaces of plunger subassembly400, ensuring that one cycle of squeezing and releasing moving arm 220only advances plunger subassembly 400 distally. All portions of handlesubassembly 200 and ratchet subassembly 300 may be formed of materialssuitable for use in surgery, including metals. Preferably, the materialsare capable of being sterilized such that handle subassembly 200 andratchet subassembly 300 may be reused. Other injector assemblies thatmay be suitable for use according to the present disclosure aredescribed in greater detail in U.S. Patent Publication No. 2015/0112352(“the '352 Publication), the contents of which are hereby incorporatedby reference herein.

Plunger subassembly 400 is illustrated in FIGS. 3A-F. Generally, plungersubassembly 400 includes a proximal shaft 410, a main shaft 420, and adistal tip portion 430. Each of proximal shaft 410, main shaft 420, anddistal tip portion 430 may be generally cylindrically, with or withoutadditional features. Proximal tip 410 may be cylindrical without anyadditional features. Main shaft 420 may also be cylindrical, but includea plurality of teeth 422 positioned along the length of the main shaft420, as best seen in FIG. 3B. Each tooth 422 may have a substantiallytrapezoidal shape in cross section, such that the distal end of eachtooth 422 has a diameter that is smaller than the diameter of theproximal end of each tooth 422. The proximal end of each tooth 422 mayhave a sharp transition into the distal end of the adjacent tooth 422 sothat the distal face of pawl 310 can easily and securely engage theproximal face of a tooth 422. All of the teeth 422 may be substantiallyidentical in shape and size as all other teeth 422. The distal tipportion 430 is best illustrated in FIG. 3C. Distal tip portion 430 mayinclude a cylindrical portion 432 having a diameter approximately equalto the diameter of the largest portion of teeth 422, with a transitioninto a recessed portion 434. A flange 436 may be positioned distal tothe recessed portion 434. Preferably, plunger subassembly 400 is formedof a metal suitable for surgical use so that plunger subassembly 400 maybe sterilized and reused, with the exception of seal member 440.

Seal member 440 is best illustrated in FIGS. 3D-E. Seal member 440 maybe formed of a rubber or plastic material suitable for a single use, asopposed to the other portions of plunger subassembly 400 that may bereusable. Seal member 440 may include a substantially flat distal face442 intended for contacting bone graft material as the plungersubassembly 400 advances due to actuation of handle subassembly 200.Seal member 440 may be substantially hollow with an opening 444 on aproximal end thereof. The hollow recess of seal member 440 may have ashape corresponding to the flange 436 and recessed portion 434 of distaltip portion 430 so that the seal member 440 may be snugly secured on thedistal tip portion 430 during use, and then removed and disposed afteruse. The connection between seal member 440 and distal tip portion 430is best seen in FIG. 3F. Seal member 440 may also include one or moreannular ridges 446. When seal member 440 is coupled to the distal tipportion 430, the ridges 446 have a diameter greater than any otherportion of plunger subassembly 400. With this configuration, whenplunger subassembly 400 is inserted within the delivery tube subassembly500, the ridges 446 of seal member 440 may have a tight fit within thedelivery tube subassembly 500.

FIG. 3G shows an example of packaging 450 that may be used to store oneor more seal members 440 prior to connection to plunger subassembly 400.Packaging 450 may be formed as a single integral piece or multiplepieces, and may be formed from any suitable material such as sturdyplastic material that is preferably translucent. Packaging 450 includesa base member 451 with two recesses 452 a, 452 b that both correspond tothe geometry of a seal member 440, so that a seal member 440 may besecurely positioned within each recess 452 a, 452 b with opening 444 ofeach seal member 440 facing away from the packaging. Packaging 450 mayinclude first and second lid portions 453 a, 453 b corresponding torecesses 452 a, 452 b. Each lid portion 453 a, 453 b may be coupled tothe base member 451 by corresponding hinge members 454 a, 454 b. Hingemembers 454 a, 454 b are shown as living hinges, although other types ofhinges may be suitable. Preferably, hinge members 454 a, 454 b arebiased so that, in the absence of applied forces, lid portions 453 a,453 b remain in the open condition shown in FIG. 3G with respect to thebase portion 451. The base portion 451 may include a base tab 455, andeach lid 453 a, 453 b may include a corresponding lid tab 456 a, 456 b.Lid tabs 456 a, 456 b may each include extensions that fold under, orinterlock with, corresponding extensions of base tab 455. With theabove-described configuration, a user may simply release the connectionbetween lid tab 456 a and base tab 455 to cause lid portion 453 a tospring open, or release the connection between lid tab 456 b and basetab 455 to cause lid portion 453 b to spring open. Once either lidportion 453 a, 453 b is opened, the corresponding seal member 440 willbe presented for use with opening 440 facing upward, as described inadditional detail below. It should be understood that in the illustratedembodiment, packaging 450 may store two identical seal members 440, withone of the seal members 440 being a spare part available for use ifnecessary. Packaging 450 could maintain a similar design but be alteredto hold one, or more than two, seal members 440 or other single-usecomponents. Preferably, for each component packaged in packaging 450, anindividual corresponding lid is provided so that any component may beaccessed while the remaining components remain secure and sterile withinpackaging 450.

Delivery tube subassembly 500 is illustrated in FIGS. 4A-D. Generally,delivery tube subassembly 500 includes a graft tube or cannula 510.Cannula 510 may include a generally hollow cylindrical body extendingfrom a proximal end to a distal end. The proximal end may include aflange member 520 including two extension members extending a lengthradially outwardly from the body of cannula 510 a distance greater thanthe diameter of the main body. A center portion of the flange member 520may include an aperture leading into the main body of cannula 510.Flange member 520 and cannula 510 may be formed integrally, or may becoupled together in any suitable fashion. The distal end of cannula 510may include a slight inward taper 530. Additional views of delivery tubeassembly 500 and portions thereof are shown in FIGS. 4B-D.

As shown in FIG. 4B, the main body of cannula 510 preferably includesindicia to mark volume or other values. For example, hash marks toindicate a volume up to 5 cubic centimeters (“cc”) in 1 cc incrementsmay be provided. Preferably, cannula 510 is formed of a transparentmaterial or other material that allows a user to see the contents insidecannula 510. For example, cannula 510 (as well as flange 520) may beformed of polycarbonate or similar materials, with the delivery tubesubassembly 500 provided sterile with the intent to dispose the deliverytube subassembly 500 after a single use. One or more radiopaque stripesmay be provided along substantially the entire length of cannula 510 sothat cannula 510 may be more easily visible, for example underfluoroscopy. In one embodiment, two stripes are provided indiametrically opposed positions along the length of cannula 510, withthe radiopaque stripes being formed of barium sulfate impregnated intothe polycarbonate material forming cannula 510. Although the particulardimensions of components of delivery tube subassembly 500 may depend onthe particular intended use, cannula 510 preferably has an innerdiameter of between about 5 mm and about 7 mm, most preferably about 6mm.

Flange 520 is shown isolated in FIG. 4C. Flange 520 includes twosymmetrical wings that extend from the aperture leading into theinterior of cannula 510. Each of the wings may have a maximum lengththat is approximately equal to the diameter of the aperture between thetwo wings, although other geometries and sizes may be appropriate. As isexplained in greater detail below, flange 520 may be used in to lock thedelivery tube subassembly 500 into a loading funnel 600 in order tofacilitate loading bone graft into the cannula 510 prior to delivery ofthe bone graft to a patient. The taper 530 at the distal end of cannula510 is shown in FIG. 4D in cross-section. As can be seen, although theexterior of cannula 510 is tapered inwardly, the interior of cannula 510at the distal end need not have any corresponding taper.

A loading funnel 600 to assist loading the delivery tube subassembly 500is illustrated in FIG. 5A. Loading funnel 600 may take the general formof an elongated cylinder or tube with a number of features thatfacilitate moving bone graft from a first source into the delivery tubesubassembly 500. For example, loading funnel 600 has a first cannuladocking end 610, a center body portion 630 extending from the cannuladocking end, and a second syringe docking end 640 opposite the cannuladocking end 610. Each section is described in more detail below.Preferably, loading funnel 600 is formed of a metal suitable for use insurgery, with the loading funnel being sterilizable and intended forreuse.

Cannula docking end 610 of loading funnel 600 is illustrated in apartially disassembled state in FIG. 5B with a locking hub member 620,which is shown in FIG. 5C, removed therefrom. Cannula docking end 610 ofloading funnel 600 may be separated from a first end 632 of center bodyportion 630 by a flange 612. Flange 612 may take the form of a circularmember integrally formed or otherwise coupled to tube 616 of cannuladocking end 610, which may be integral with the first end 632 of centerbody portion 630, with the flange 612 extending radially outward of thetube. Flange 612 may provide a contact point for a spring 614, which asillustrated takes the form of a wave spring. The terminal end of cannuladocking end 610 may include two diametrically opposed extensions 618. Asdescribed in greater detail below, the extensions 618 may be shaped anddimensioned so that the flange 520 of delivery tube subassembly 500mates or otherwise locks or couples with extensions 618 in only twoorientations. Extensions 618 may also extend radially outward of tube616 to provide a surface for locking hub 620, described below, to abut.

Locking hub 620 may include a substantially cylindrical body portion 622with a hollow cylindrical center adapted to fit over tube 616 of cannuladocking end 610. Locking hub 620 may be rotatable with respect to tube616, with a plurality of grooves or other friction members or other gripmembers provided to facilitate a user in rotating locking hub 620. Oneend of locking hub 620, when assembled on tube 616, may abut spring 614.The other end of locking hub 620 may include a flat face 624 adapted toabut extensions 618. When locking hub 620 is assembled to tube 616 withface 624 abutting extensions 618, spring 614 may be in a compressedstate so that a continuous force is applied to locking hub 620, pushinglocking hub 620 against extensions 618. With this configuration,friction may be created or provided so that locking hub 620 is unlikelyto rotate with respect to tube 616 in the absence of intentionallyapplied rotational forces. Two extensions 626 may extend both radiallyoutwardly and axially away from face 624, each extension 626 including arecess 628 that has a substantially arcuate shape. The arcuate shape ofrecesses 628 may correspond to the shape of the wings of the flange 520of cannula 510. With this configuration, as is described in additionaldetail below, flange 520 may be positioned between extensions 618 whileextensions 626 substantially align with extensions 618. Then, lockinghub 620 may be rotated approximately ninety degrees clockwise orcounterclockwise until extensions 626 are staggered with respect toextensions 618. In this rotated position, the wings of the flange 520 ofcannula 510 may be positioned within recesses 628 formed by extensions626, with the flange 520 being effectively locked in place because thewings of flange 520 are too large to clear the extensions 626 if theflange 520 is pulled out of the loading funnel 600.

Syringe docking end 640 of loading funnel 600 is illustrated in apartially isolated state in FIG. 5D, with a transfer hub member 650shown fully isolated in FIGS. 5E-F. Second end of 636 of center bodyportion 630 may extend from the first end 632 and join transfer hubmember 650, for example by being coupled or integrally formed therewith.Transfer hub member 650 may include a syringe dock 652. Syringe dock 652may include a substantially cylindrical wall defining a recess having alongitudinal axis that is orthogonal to the main longitudinal axis ofdocking funnel 600. Syringe dock 652 may include mating features, suchas internal threads, to mate with corresponding external threads 750 ofa syringe member 700, described in greater detail below. The syringedock 652 leads into a holding area 654. As is described below, oncesyringe member 700 is coupled to syringe dock 652, a user may advancebone graft into the holding area 654.

A face 656 of transfer hub member 650 may have a concave profile as bestseen in FIG. 5E. Once bone graft has entered into holding area 654, auser may advance a loading tool 800, described in greater detail below,into holding area 654 to advance bone graft through an aperture 658 intransfer hub member 650. The distal end 530 of cannula 510 may bepositioned adjacent aperture 658 when cannula 510 is assembled withinloading funnel 600, so that bone graft in holding area 654 may beadvanced into cannula 510. Preferably, the diameter of aperture 658 isslightly smaller than the inner diameter of cannula 510 to helpfacilitate bone graft transferring through the aperture 658 into cannula510. For example, if the inner diameter of the cannula is about 6 mm,aperture 658 preferably has a diameter of between about 5.5 mm and about6 mm, most preferably about 5.7 mm and about 5.8 mm. The concave profileof face 656 may facilitate in guiding the loading tool 800 into holdingarea 654.

Referring again to FIG. 5A, the center body portion 630 of loadingfunnel 600 may be substantially cylindrical, including a first end 632and a second end 636. The first end 632 may include a plurality of slots633 extending along a portion of the length thereof, which may be spacedevenly around the circumference of first end 632. Similarly, the secondend 636 may include a plurality of slots 637 extending along a portionof the length thereof, which may be also be spaced evenly around thecircumference of second end 636. In the illustrated embodiment, thefirst end 632 and second end 636 each include four slots 633, 637.Whether formed integrally or joined together, a continuous passagewaymay be formed along the length of both first end 632 and second end 636,the passageway sized and shaped to receive cannula 510 therethrough. Asdescribed in greater detail below, the slots 633 and 637 may lead intothe passageway so that a user can view indicia on cannula 510 whileloading the cannula 510. The slots 633 and 637 may also provide forweight reduction of loading funnel 600. One or both of the first end 632and second end 636 may include features, such as ridges in second end636, to facilitate a user in gripping that portion of the loading funnel600.

Syringe member 700 is illustrated in FIGS. 6A-B. The components ofsyringe member 700 may be formed of material intended for a single useand to be disposable, such as a clear plastic material such aspolycarbonate. As shown in FIG. 6A, syringe member 700 may include aplunger member and a housing member. The plunger member may include ashaft 710 with a grip member 720, which may take the form of asubstantially flat surface, at a proximal end of the shaft 710, and aseal 730 at a distal end of the shaft 710. The plunger fits snuglywithin a shaft 740 of the housing, which may be substantiallycylindrical and hollow, preferably with the seal 730 forming an airtightseal with the shaft 740 of the housing. In some embodiments, seal 730may be formed of a rubber or another elastomeric material to helpfacilitate the formation of an airtight or substantially airtight seal.Mating features such as external threads 750 may be formed on a distalend of the shaft 740, the external threads 750 corresponding to theinternal threads of the syringe dock 652 of loading funnel 600. Shaft740 also preferably includes indicia 760 which may be hash marks toindicate some quantity, such as volume of bone graft loaded into thesyringe member 700. As noted above, shaft 740 is preferably translucentso that the contents of syringe member 700 may be easily seen andcompared with indicia 760.

A loading tool 800 for use in driving bone graft from holding area 654into cannula 510 is illustrated in FIGS. 7A-C. Loading tool 800 mayinclude a handle 810, shaft members 820, 830, and a distal tip 840.Handle 810 may be formed from a material suitable for use in surgery,including metal or rubber that provides a suitable grip, preferablywhere the material may be sterilized and reused. Handle 810 may have arounded proximal end that transitions into a narrow rounded distal end.Preferably, handle 810 does not include any substantially flat surfaces,which may facilitate a user in gripping handle 810 using different gripconfigurations. The distal end of handle 810 may include texturizedsurfaces such as ridges 812, which may facilitate the user's grip onhandle 810. Shaft 820 may extend into handle 810 and be securely coupledthereto. Shaft 820 may transition into a narrow substantiallycylindrical shaft 830, which itself may transition into distal tip 840.Shafts 820, 830 and distal tip 830 may be formed as a unitary piece ofmaterial and may be formed from metal or other material suitable forsurgery, particularly materials that may be sterilized so that loadingtool 800 may be reused in different procedures. As best seen in FIG. 7C,the distal tip 840 may be substantially in the shape of a half-cylinder842 which may be approximately half the size of the cylindrical shaft830. The distalmost end of distal tip 840 may have a concave recess 844in the shape of a part of a sphere or other similar shape. The shape ofthe distal tip 840 may provide extra flexibility for the user in termsof the user's ability to pack bone graft from holding area 654 intocannula 510. Shaft member 830 may have a diameter of between about 2 mmand 4 mm, most preferably about 3 mm. Tip 840 may be about half the sizeof shaft member 830. Preferably, the diameter of shaft 830 is smallenough compared to the inner diameter of cannula 510 so that space isavailable between the shaft 830 and the cannula 510 when the shaft 830is inside the cannula 510, which may facilitate better manipulation andplacement of bone graft during the loading of cannula 510. The use allof the above components, including loading tool 800, to load cannula 510with bone graft is discussed in greater detail below.

A flowchart illustrating a method of loading the delivery tubesubassembly is provided in FIG. 8. In a first step, the plungersubassembly 400 may be taken, for example from a container containingre-usable sterilized instruments, and the distal tip 430 may be pressedonto plunger seal 440, which itself may be taken from a separatecontainer of disposable components, as shown in FIG. 9A. Then, theplunger subassembly 400 may be inserted into the delivery tubesubassembly 500, with the leading end with seal 440 inserted through theaperture in the flange 520 of delivery tube subassembly 500, as shown inFIG. 9B. The delivery tube subassembly 500 may be provided in containeror as part of the same kit as the seal 440. The seal 440 preferablyforms a fluid tight and/or air tight seal with cannula 510. The distalface of seal 440 should be inserted to a position within cannula 510based on the amount of volume of bone graft that the user desires toload into cannula 510. For example, if the surgical procedure calls forloading 5 cc of bone graft into the cannula 510, the distal face of seal440 should be inserted to the hash mark on cannula 510 indicating 5 cc.As noted above, the cannula 510 is preferably translucent to facilitatethis positioning. The tight fit between cannula 510 and seal 440facilitates the user handling the assembled items without worrying thatthe position of seal 440 with respect to cannula 510 will shift withoutintentional force applied to change the position of seal 440. With thedistal face of seal 440 in the desired position and the cannula 510friction fit with the plunger subassembly 400, the user then inserts theassembled components into the cannula docking end 610 of loading funnel600. The length of cannula 510 is sized so that as the distal end 530 ofcannula 510 becomes adjacent the aperture 658 in transfer hub member650, the flange 530 of cannula 510 makes contact with the flat face 624of locking hub 620, with the flange 530 positioned between extensions618 of cannula docking end 610, as shown in FIG. 9C. Then, the userrotates locking hub 620 approximately 90 degrees clockwise andcounterclockwise, until the wings of flange 520 are positioned betweenthe flat face 624 and extensions 626 of cannula docking end 610, asshown in FIG. 9D. In this condition, the plunger subassembly 400 anddelivery tube subassembly 500 are in a locked position with respect toloading funnel 600. In an embodiment in which cannula 510 includes hashmarks of 1 cc, 2 cc, 3 cc, 4 cc, and 5 cc, the 4 cc and 5 cc indicia maybe visible through slots 633, with the 2 cc and 3 cc indicia visiblethrough slots 637, although other configurations are possible.

In a separate group of steps, which may occur in any time relation withrespect to the three described in the paragraph above, the user loadsbone graft into the shaft 740 of string member 700 and couples thesyringe member 700 to the loading funnel 600. One example of a suitablebone graft substitute material may be Vitoss® Bone Graft Substitute,Vitoss® Bioactive Foam Back Bone Graft Substitute, or other products inthe Vitoss® line sold by Stryker Corp. Examples of suitable bone graftmaterials are described in greater detail in U.S. Pat. Nos. 7,534,451,6,383,519 and 6,521,246 and in U.S. Patent Publication No. 2005/0288795,the disclosures of which are both hereby incorporated by referenceherein. The bone graft may be packed into the shaft 740 of syringemember 700 by hand or other suitable method to a desired volume. Forexample, if 5 cc of bone graft is desired, the seal 730 of syringemember 700 may be advanced to the corresponding 5 cc (or 5 mL) hash markon the indicia 760 of shaft 740, as shown in FIG. 9E. As noted above,shaft 740 is preferably translucent so that a user can easily confirmthe position of the seal 740. The user then may hand pack bone graft tofill shaft 740. Although a significant benefit of the system describedherein is the capability of a user to use any desired bone graftmaterial in syringe member 700, as opposed to providing a pre-packedsyringe, in some embodiments a syringe pre-packed with bone graft may beprovided with the system. Once the syringe member 700 is loaded, theuser may couple the mating features 750 of syringe member 700 with thecorresponding mating features in syringe dock 652, for example byscrewing threads of the syringe member 700 to corresponding threads ofsyringe dock 652, as shown in FIG. 9F. The connection between syringemember 700 and syringe dock 652 may be airtight or substantiallyairtight. This seal, as well as the seal between seal 440 and cannula510, may be particularly helpful when the bone graft material has aliquid component that might otherwise leak out of a non-sealed portionof the system. Although it was noted above that the first five stepsdescribed above may be completed in any order, it is preferable that theplunger 400 and cannula 510 are assembled to the loading funnel 600prior to the loaded syringe member 700 being coupled to the loadingfunnel 600, so that upon connection of the loaded syringe member 700 tothe loading funnel 600, the cannula 510 is immediately ready to beloaded.

With the loaded syringe member 600 and the plunger 400 and cannula 510coupled to loading funnel 600, the user may begin loading the cannula510. In order to load the cannula 510, the user first fills at least aportion of holding area 654 with bone graft by advancing the shaft 710of syringe member 700 distally. Once the user visually confirms that asuitable amount of bone graft is positioned within holding area 654, theuser may advance the distal tip 840 and shaft 830 of loading tool 800through the holding area 654, through the adjacent aperture 658, andinto cannula 510, pushing at least some bone graft from the holding area654 into the cannula 510 as shown in FIG. 9G. Preferably, the userinitially advances the bone graft to a position adjacent the seal 440 ofplunger subassembly 400. The user may then determine whether the cannula510 is fully loaded with bone graft. If the cannula 510 is not fullyloaded, the user may remove loading tool 800, advance the shaft 710 ofsyringe member 700 to once again fill holding area 654 with bone graft,and then using the loading tool 800 to further fill cannula 510. Theuser may iteratively repeat this process until the cannula 510 is fullyloaded with bone graft with the desired volume. Preferably, pieces ofthe bone graft are all smaller than about 5 mm, particularly if cannula510 has an inner diameter of about 6 mm.

The recess 844 of the loading tool 800 may provide the user thecapability of scooping, cutting, breaking, or otherwise easilymanipulating the bone graft material during loading of the cannula 510.Similarly, the substantially half-cylinder 842 of distal tip 840 mayprovide additional capability for the user to position the bone graft asdesired. In other words, these varied shapes may provide additionalmaneuverability and control for the user compared to a loading tool thatis solely formed as a cylinder.

The configuration above provides a number of additional benefits notalready noted. For example, referring to the partially transparent viewof syringe docking end 640 in FIG. 10, it can be seen that the syringemember 700 is capable of advancing bone graft into holding area 654without any significant amount of tapering. In particular, the syringemember 700 itself does not have a significant taper in the distal end ofshaft 740. In addition, the holding area 654, as best seen in FIG. 5F,is shaped so that at the point where the distal end of syringe member700 is adjacent holding area 654, there is not a significant taper atthe transition point. Many bone graft materials behave, at least inpart, as non-Newtonian fluids that vary in viscosity depending onhydraulic forces and time. Because of this, as bone graft is pushedthrough a tube, pressure may build causing difficulty in moving the bonegraft to the intended position. This problem may be amplified when thegeometry of the tube which the bone graft is moving begins to taper orotherwise narrow. The geometry of syringe member 700 as well as thetransition from syringe member 700 to holding area 654 helps avoid thisproblem because the bone graft does not encounter any significant taper,and further because there is a very short stroke required to move thebone graft from the distal end of the syringe member 700 into theholding area 654. These features may make the loading processsignificantly easier than in prior systems.

Other benefits may be provided by the “L” shaped loading configurationdescribed above. More particularly, as noted above and best seen in FIG.9G, when the syringe member 700 and the cannula 510 are assembled to theloading funnel 600, the main longitudinal axis of syringe member 700 issubstantially orthogonal to the main longitudinal axis of cannula 510.This further facilitates a short stroke of the syringe member 700 tomove the bone graft in a first direction into the holding area 654, withthat small amount of material then moved along a substantiallyorthogonal axis into cannula 510 using loading tool 800. Thisconfiguration allows for an easier and more easily controlled loading ofcannula 510 than, for example, if the entire loading from a syringe to adelivery cannula was along a single axis.

Referring again to FIG. 8, once the user determines that the cannula 510is loaded with the desired volume of bone graft, the user may remove theloading tool 800 and then rotate locking hub 620 approximately ninetydegrees in either the clockwise or counterclockwise direction to unlockthe flange 520 of cannula 510 from loading funnel 600. In the unlockedcondition, the cannula 510 and the plunger subassembly 400 may both beremoved from the loading funnel 600. The assembled cannula 510 andplunger 400 may then be coupled to handle subassembly 200. Referringback to FIG. 2A, one of the wings of the flange 520 of cannula 510 issnapped or otherwise coupled to the corresponding slot of secondretaining feature 250. Similarly, a portion of the shaft 420 of plungersubassembly 400 extending beyond the flange 520 may be snapped orotherwise coupled to first retaining feature 240. In this position, thedistal face of pawl 320 is positioned between two adjacent teeth 422 ofshaft 420. Once in the fully assembled condition shown in FIG. 1, theuser may advance the distal tip of 530 of cannula 510 to the desiredposition in the patient's body. Bone graft may be ejected from thedistal tip 530 of cannula 510 by squeezing moving handle 220 towardfixed handle 210, causing pawl 320 to push the shaft 420 of plunger 400distally with respect to cannula 510. The user may then relax the gripon moving handle 220, and repeat the process to iteratively andincrementally expel bone graft from the distal tip 530 of cannula 510into the desired location in the patient. The user may continue toadvance plunger 400 distally until the pawl 320 is adjacent the proximalportion 410 of the plunger 400 which contains no teeth as a safetyfeature. At this point, the user can no longer advance plunger 400 bysqueezing handles 220 and 210, helping to ensure the user cannotunintentionally advance the plunger 400 through the cannula 510 and intothe surgical site.

Once the user expels the desired amount of bone graft from cannula 510,the assembly may be removed from the patient and the surgical procedurecompleted as desired. In order to disassemble the cannula 510 andplunger 400 from handle subassembly 200, the user may lay the handlesubassembly on a flat surface, such as a surgical table or accessorytable, with the open ends of retaining features 240, 250 facing awayfrom the surface of the table. In this position, the wing of flange 520extending through the slot of second retaining feature 250 contacts thesurface of the table, with the second retaining feature 250 remainingspaced from the table. The user can then press the handle subassembly200 forcefully toward the table, causing a corresponding force to pushthe wing of flange 520 contacting the table away from the table, causingthe cannula 510 and plunger 400 to dislodge from the handle subassembly.Any disposable components, such as the delivery tube subassembly 500,the seal 440 of plunger subassembly 400, and the syringe member 400 mayall be discarded. Any reusable portions, such as the remaining portionsof plunger subassembly 400, the loading funnel 600, the handlesubassembly 200, and the loading tool 800, may then be sterilized foruse in another procedure. Although the assembly disclosed herein may beused in any desired surgical procedure, it may be particularly usefulfor use in facet joints of the spine or for delivery into theintervertebral space, similar to procedures described in greater detailin the '352 Publication.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims. For example,one embodiment of an assembly or subassembly described above may becombined with other embodiments of assemblies or subassemblies describedabove.

It will be appreciated that the various dependent claims and thefeatures set forth therein can be combined in different ways thanpresented in the initial claims. It will also be appreciated that thefeatures described in connection with individual embodiments may beshared with others of the described embodiments.

1. A method of loading bone graft into a bone graft delivery system, themethod comprising: coupling a container having the bone graft therein toa loading member so that a longitudinal axis of the container istransverse to a longitudinal axis of the loading member; positioning acannula within a passageway of the loading member so that a longitudinalaxis of the cannula is parallel to the longitudinal axis of the loadingmember; advancing a first amount of the bone graft from the container tothe loading member; and inserting a loading tool into an interior spaceof the loading member to advance at least a portion of the first amountof bone graft from the interior space of the loading member into thecannula.
 2. The method of claim 1, further comprising: after advancingthe portion of the first amount of bone graft into the cannula,advancing a second amount of the bone graft from the container to theloading member; and inserting the loading tool into the interior spaceof the loading member to advance at least a portion of the second amountof bone graft from the interior space of the loading member into thecannula.
 3. The method of claim 1, wherein the container is a syringemember.
 4. The method of claim 3, wherein coupling the container to theloading member includes threading a threaded portion of the syringemember into a threaded docking portion of the loading member.
 5. Themethod of claim 1, further comprising inserting a plunger member into aninterior space of the cannula prior to positioning the cannula withinthe passageway of the loading member.
 6. The method of claim 5, furthercomprising: removing the cannula from the loading member while theplunger member is still within the cannula.
 7. The method of claim 6,further comprising coupling the cannula and the plunger member to ahandle assembly adapted to advance the plunger member relative to thecannula.
 8. The method of claim 5, further comprising coupling anelastomeric seal onto a distal tip of the plunger member prior toinserting the plunger member into the interior space of the cannula. 9.The method of claim 8, wherein inserting the plunger member into theinterior space of the cannula includes forming a fluid tight sealbetween the elastomeric seal and the interior space of the cannula. 10.The method of claim 8, wherein the elastomeric seal is stored within asterile package prior to coupling the elastomeric seal onto the distaltip of the plunger member.
 11. The method of claim 10, wherein thesterile package includes a base portion connected to a lid portion by ahinge, the hinge biasing the lid portion away from the base portion intoan open condition in the absence of applied force.
 12. The method ofclaim 1, wherein positioning the cannula within the passageway of theloading member includes advancing the cannula until a proximal flange ofthe cannula contacts the loading member.
 13. The method of claim 12,further comprising rotating a locking hub of the loading member so thatextension members of the locking hub overlie the proximal flange of thecannula.
 14. The method of claim 1, further comprising manually loadingthe bone graft into the container prior to coupling the container to theloading member.
 15. The method of claim 1, wherein coupling thecontainer to the loading member results in the longitudinal axis of thecontainer is orthogonal to the longitudinal axis of the loading member.16. The method of claim 1, wherein advancing the first amount of thebone graft from the container to the loading member includes advancingthe first amount of the bone graft from the container into a holdingarea of the loading member that is spaced apart from the cannula. 17.The method of claim 16, wherein inserting the loading tool into theinterior space of the loading member includes inserting the loading toolthrough the holding area.
 18. The method of claim 16, whereinpositioning the cannula within the passageway of the loading memberincludes positioning a distal open end of the cannula adjacent theholding area.
 19. The method of claim 1, wherein the loading memberincludes at least one viewing slot that opens to the passageway withinthe loading member.
 20. The method of claim 19, wherein the cannulaincludes at least one volume indicator visible through the at least oneviewing slot when the cannula is positioned within the passageway of theloading member.